Using Wi-Fi at 35,000 Feet

A. Yes, if you happen to be flying on an airline that offers the service. International carriers like Korean Air, Lufthansa and Singapore Airlines already have wireless broadband service on many routes; fees for using it vary. Check with your airline to see if it offers in-flight Internet.

Boeing's Connexion system, which uses satellites to provide Internet access, is used by many European and Asian airlines to let passengers surf the Web and exchange e-mail messages on wireless laptops and devices. Some airlines are also experimenting with ground-based towers to transmit the network signal.

Last year, United Airlines was the first American carrier to announce it had approval from the Federal Aviation Administration to install wireless networking equipment on its planes. It plans to offer onboard Wi-Fi service through Verizon Airfone, if Verizon can obtain the needed frequencies for a ground-based system in a Federal Communications Commission auction.

Word Templates

In Action

Q. What is the Normal.dot file in Word?

A. Microsoft Word uses two basic file types. One is the document format (.doc), the default file type for the regular word-processing files you create with the program. The second format is for document templates, and uses the .dot extension.

The Normal.dot file is the global template Word uses as a basis for most new documents you create with the program. The first time you use Word, the program creates its own Normal.dot file with default settings for margins, fonts and other document properties.

You can change the settings of the Normal template if you don't like the default look for your documents, but changes made to this global template affect other documents based on it. (If you get a message about saving a change to the Normal.dot file, and didn't intend to make one, don't click the O.K. button.)

You can create customized templates in Word for the occasions when you want certain types of documents, like letterheads or cover sheets, to use settings other than your default ones. Once you have designed or modified a new document, go to the File menu, choose Save As and select Document Template as the format. Later, when you create a new document based on that customized template, all of your modifications will already be in place.

Replacing

A Broken CD Drive

Q. The CD drive on my laptop has been broken for almost a year. Is it possible to replace the drive myself, or do I need to go to a service center?

A. There are plenty of Web sites around that can help you find the right replacement parts for your laptop, as well as any other hardware you may need to make sure the new drive fits properly. Two such sites are PC Hub (www.pchub.com) and the Spare Parts Warehouse (www.sparepartswarehouse.com).

How simple it is to swap in the new drive, however, can depend on the laptop's design and where the drive is inside the machine. Laptops from some manufacturers have the disc drive in an easy-to-reach bay on the side of the machine that lets you pop out the drive with the touch of a button. On other models, you may need to unscrew the bottom of the computer or temporarily lift up the keyboard to get to the CD drive. Check your computer's manual or manufacturer's Web site for instructions on how to locate the drive or replace it.

Having a computer-repair professional do the job for you may be more expensive, but can save you the anxiety of opening your laptop. Out-of-warranty repairs with parts and service included can cost more than $100. If there is no authorized service center for your brand in your area, you can probably find help in a large chain store like CompUSA, Staples or Best Buy (which has the Geek Squad, a department dedicated to computer maintenance and repairs).

If you can part with the laptop for a week or so, a mail-based technician may be a less expensive option. The Web sites mentioned above have a mail-in repair service, as do sites like Tech Restore (www.techrestore.com), which fixes PC and Macintosh laptops, iPods and even Sony PlayStation Portables.

Questions about computer-based technology may be sent to QandA @nytimes.com. This weekly column will address questions of general interest, but e-mail and letters cannot be answered individually.